Grammar error in the Rainbow poem

All the first letters of the first words in the lines should be in capital letters if that line is actually finished.

[As you can see in this poem](https://reedsy.com/discovery/blog/love-poems).

No file or test is named in the issue. Start by locating the Rainbow poem content in the repository and compare its line beginnings with the linked poem reference. Done means capitalizing the first letter of each line's first word where the line is a complete sentence or thought.

Written by the indexing model from the issue text.